This is the module which uses the "menu" module position. Basically this is a module and it is independent from "menu manager", which means, you can type anything in there. Just pick the "menu" position for that module and Boom! this module will appear here.

You can design the content, add some pictures in it etc.. and it will be shown here inside a dropdowned menu item.

In this example, you are reading the content of the module, and the name of the module is "Custom HTML".